1991 Nippon Professional Baseball season
| 1991 NPB season | |
|---|---|
| League | Nippon Professional Baseball |
| Sport | Baseball |
| Regular season | |
| Season MVP | CL: Shinji Sasaoka (HIR) PL: Taigen Kaku (SEI) |
| League postseason | |
| CL champions | Hiroshima Toyo Carp |
| CL runners-up | Chunichi Dragons |
| PL champions | Seibu Lions |
| PL runners-up | Kintetsu Buffaloes |
| Japan Series | |
| Champions | Seibu Lions |
| Runners-up | Hiroshima Toyo Carp |
| Finals MVP | Koji Akiyama (SEI) |
The 1991 Nippon Professional Baseball season was the 42nd season of operation for the league.